Glass plate having electrically charge-preventive film of conductive organic polymer, its making method, a solution for making the film, and its manufacturing method

ABSTRACT

A glass plate having high-electroconductive film which can be formed using electroconductive organic polyrmer in a simple method and at a low cost, and having an improved anti-static characteristic with a strong film hardness and a strong adhesive strength. The glass plate has an anti-static film ( 10, 20 ) formed on the exterior surface, the film comprising a first coating layer ( 11, 21 ) formed containing an electroconductive organic polymeric component and a second coating layer ( 12, 22 ) of silica coating formed by being overcoated onto the first coating layer ( 11, 21 ). The electroconductive organic polymeric solution contains 0.005-0.5 wt. % of polyethylenedioxythiophene which polystyrenesulphonate is doped to and silicon alkoxide of below 10 wt. %, and also may contain 40-90 wt. % of at least one a selected from a group consisting of a methanol, an ethanol, an isopropanol, a butanol, and combinations thereof, 5-70 wt. % of pure water, and 1-20 wt. % of at least one co-solvent selected from a group consisting of a compound having a carbonyl group, an ether, and combinations thereof.

FIELD OF THE INVENTION

The present invention relates to a glass plate having electricallycharge-preventive film of conductive organic polymer, its making method,a solution for making the film, and its manufacturing method. In detail,it relates to an anti-static film formed using electroconductive organicpolymer on the surface of the glass plate, particularly, an imagedisplay faceplate or a screen portion in a panel of a CRT 1 so as toimprove the electrically charge-preventive so anti-staticcharacteristics of the glass plate, such as the image display faceplate.

Recently, a wide use of an anti-explosion type cathode ray tube allows aface cover glass to be unnecessary in a television receiver, a monitor,etc., regarding the prevention of electrostatic charge, thereby exposingthe front portion of the cathode ray tube, and giving electric shock bycharged electrical high voltage, to the person who comes access, to thefaceplate of the cathode ray tube. Furthermore, dust in air, particles,etc., are adhered to by the electric force, and accumulated on, thecharged faceplate of the cathode ray tube, thereby having the image onthe display faceplate difficult to see.

The cause of electrostatic charge as to the faceplate panel as oneexample of the glass plate is as follows.

A thin and uniform aluminium film is deposited by vacuum on the phosphorscreen structure on the interior surface of the faceplate panel. When aelectric power is applied to, a high anode voltage is applied to thealuminium film. Electric charges generate on the exterior surface wallof the panel by electrostatic induction due to the high voltage of theinside aluminium film.

Korean patent publication No. 2713 as one prior arts for providing ananti-static characteristics on the image display faceplate describes onesuch anti-static coating formed by the steps of preparing a slurry bymixing an alcohol solution containing alkoxysilane Si(OR)₄ (R is analkyl group) and at least one of tin oxide, indium oxide and antimonyoxide, spraying the slurry on the faceplate panel, and heat-treating thesprayed panel at a relatively low temperature.

U.S. Pat. No. 5,750,054, issued to Patrizia Cinquina, Vasto, et al. onMay 12, 1998, discloses an anti-static, anti-glare coating for areflective-transmissive surface wherein the surface is applied onto witha coating solution comprising a thiophene-based, electroconductivepolymer and a siliceous material. As the concrete electroconductivepolymer, polyethylenedioxythiophene, and as a siliceous material,lithium-stabilized silica sol and tetraethoxysilane are disclosed.

Further, U.S. Pat. No. 5,742,119 issued to Aben, et al. on Apr. 21,1998, discloses a display screen of a cathode ray tube provided with anelectroconductive coating of poly-3,4-ethylenedioxythiophene. Thecoating layer has a sheet resistance of 1 kilo-ohm/quadrature and a hightransmission. The layer provides an effective shield againstelectromagnetic radiation. The coating can be provided with additionallayers of, for example, silicon dioxide to improve the mechanicalproperties.

However, the metallic oxide costs too much, thereby making themanufacturing cost very high.

Further, the problem is that while the metallic oxide exists dispersedlyin the alcohol solution, deposition problem arises due to cohesionbetween the particles according the condition of the surroundings,thereby making spots or unevenness and lowering the electroconductivity.

Accordingly, it is one object of the present invention to provide aglass plate such as image display faceplate havinghigh-electroconductive film which can be formed using electroconductiveorganic polymer in a simple method and at a low cost, and have animproved anti-static characteristic with a strong film hardness and astrong adhesive strength. Also, the present invention provides a methodof making such film , said method comprising the steps of obtaining aanti-static layer by dissolving in alcohol an aqueous solution ofelectroconductive organic polymers and applying the resultant dissolvedsolution, and then spin overcoating an alcoholic solution of siliconalkoxide and heat-treating the resultant overcoated film. If necessary,an additional anti-glare layer may be further formed by spraying thealcoholic solution of silicon alkoxide onto the anti-static layer or theresultant film of the alcoholic solution of silicon alkoxide.

SUMMARY OF THE INVENTION

To accomplish the aforementioned purpose, the present invention providesa glass plate on which an anti-static film is formed on the exteriorsurface, said film comprising a first coating layer formed containing anelectroconductive organic polymeric component and a second coating layerof silica coating formed by being overcoated onto the first coatinglayer.

Said first coating layer may be formed by coating an electroconductiveorganic polymeric solution containing 0.005-0.5 wt. % ofpolyethylenedioxythiophene which polystyrenesulphonate is doped to andsilicon alkoxide of below 10 wt. %, and said electroconductive organicpolymeric solution may contain 40-90 wt. % of at least one alcoholicsolvent selected from a group consisting of a methanol, an ethanol, anisopropanol, a butanol, and combinations thereof, 5-70 wt. % of purewater, and 1-20 wt. % of at least one co-solvent selected from a groupconsisting of a compound having a carbonyl group, an ether, andcombinations thereof. And, said second coating layer is formed byovercoating with alkoxysilane Si(OR)₄.

The anti-static film may have an anti-glare characteristic itself, andotherwise at least one anti-glare film formed thereon. Such glass platemay be an image display faceplate or a screen portion in a panel of aCRT.

Also, the present invention provides a method of forming a anti-staticfilm on a surface of a glass plate, the method comprising the steps of:first-coating an electroconductive organic polymeric solution on thesurface of the glass plate, said solution containing 0.005-0.5 wt. % ofpolyethylenedioxythiophene which polystyrenesulphonate is doped to andsilicon alkoxide of below 10 wt. %; and second-coating alkoxysilaneSi(OR)₄ after the first-coating step.

Furthermore, the present invention provides a solution for applying ontoa surface of a glass plate in order to form an anti-static film, saidsolution containing 0.005-0.5 wt. % of polyethylenedioxythiophene whichpolystyrenesulphonate is doped to, silicon alkoxide of below 10 wt. %,40-90 wt. % of at least one alcoholic solvent selected from a groupconsisting of a methanol, an ethanol, an isopropanol, a butanol, andcombinations thereof, 5-70 wt. % of pure water, and 1-20 wt. % of atleast one co-solvent selected from a group consisting of a compoundhaving a carbonyl group, an ether, and combinations thereof.

It is preferred, in the electroconductivity, that said solution containsaid silicon alkoxide of below 2 wt. %.

Furthermore, the present invention provides a method of making asolution for applying onto a surface of a glass plate in order to forman anti-static film, said solution being prepared by the steps of:dissolving in alcohol an aqueous solution of electroconductive organicpolymers; first-adding silicon alkoxide to the alcoholic solution forimproving the cohesive strength; and second-adding pure water and aninorganic acid catalyst for hydrolysis, and co-solvent for improving theapplication property.

The anti-static film formed by such method, comprises a first coatinglayer having fine porosities and an excellent electroconductiveproperty, and a second coating layer formed by being overcoated with amaterial of a strong adhesive strength onto the first coating layer soas to adhere to at least the glass plate by penetrating through theporosities of the first coating layer, thus the anti-static film isadhered to the glass plate due to the strong adhesive strength withoutbeing scaled off and with obtaining an excellent electroconductivecharacteristic of the first coating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the principle and nature of the presentinvention reference should be made to the following detailed descriptiontaken in connection with the accompanying drawings in which:

FIG. 1 is a schematical side view partially in axial section of a colorcathode-ray tube, wherein an electroconductive organic polymericanti-static film is formed on the exterior surface of a faceplate panelthereof according to one embodiment of the present invention;

FIG. 2 is an enlarged sectional view of one portion in a panel in FIG.1;

FIG. 3 is an enlarged sectional view similar to FIG. 2, showing anelectroconductive organic polymeric anti-static film formed on a generalglass plate according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 and FIG. 2 show a color cathode ray tube as one example of animage display faceplate among a glass plate for an explanation of oneembodiment of the present invention.

In FIG. 1, an electroconductive organic polymeric anti-static film 10 isformed on the exterior surface of a faceplate panel 2 in a color cathoderay tube 1. A grounded anti-explosion band 4 comes into contact with theanti-static film 10 and makes the potential of the overall surface ofthe anti-static film 10 zero, thereby preventing electrical charge.

In FIGS. 1 and 2, the anti-static film 10 according to the presentinvention comprises a first coating layer 11 formed containing anelectroconductive organic polymeric component and a second coating layer12 of silica coating formed by being overcoated onto the first coatinglayer 11, being characterizing in that the first coating layer 11 hasfine porosities 11 ′ and an excellent electroconductive property, andthat the second coating layer 12 adheres to at least the glass plate 2′with a strong adhesive strength by penetrating through the porosities11′, 21′ of the first coating layer 11, 21. Embodiments according to thepresent invention, using an electroconductive organic polymeric solutioncontaining 0.005-0.5 wt. % of polyethylenedioxythiophene whichpolystyrenesulphonate is doped to as the organic polymer of the firstcoating layer 11, and using alkoxysilane Si(OR)₄ (R is an alkyl group asa solution for making said second coating layer 12, are explained asfollows.

EXAMPLE 1

In FIGS. 1 and 2, the anti-static film 10 is formed according to thepresent invention as follows.

That is, an aqueous solution of polyethylenedioxythiophene(PEDT/PSS)which polystyrene sulphonate is doped to is dissolved in methanol.Sequently, ethylsilicate(Si(OC₂H₅)₄) as an adhesive agent is added tothe aqueous solution(PEDT/PSS aqueous solution), thereby theelectroconductive solution being prepared. Then, pure water and aninorganic acid catalyst for hydrolysis, for example hydrochloric acid(HCl) are added, and dispersion agent is finally added, thus anelectroconductive organic polymeric solutions prepared. Then, in anupward state of the exterior surface of the faceplate panel 2 of thecolor cathode ray tube 1, the color cathode ray tube 1 is rotated witharound 130 rpm and the prepared solution is dropped on the exteriorsurface of the faceplate panel 2, thus a first coating layer 11 of athin and uniform thickness is formed. This spin-coating is completed forabout 1 minute 10 seconds. Following this spin-coating, a second coatinglayer 12 is formed by spin-coating alkoxysilane(Si(OR)₄) on the firstcoating layer 11, thereby making the anti-static film 10 as shown inFIG. 2 with an excellent adhesion between the first coating layer 11 andthe panel 2. This spin-coating is completed for about 1 minute 20seconds. At the last time, the anti-static film 10 is baked at aboveabout 150 degrees centigrade for 30 minutes, thereby the anti-staticfilm 10 comprising the first coating layer 11 and the second coatinglayer 12 being completely formed.

The constituents and the contents of the electroconductive organicpolymeric solution for forming the first coating layer 11 are asfollows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHYL SILICATE  0.50 wt. % ETHANOL60.19 wt. % ISOPROPANOL 10.00 wt. % PURE WATER 25.00 wt. % HYDROCHLORICACID (HCl, 35%)  0.01 wt. % N-METHYL-2-PYRROLIDONE  2.00 wt. % ETHYLCELLOSOLVE  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1. Surface resistivity: 9*10³ ohms/sq. (Ω/□)

2. Film hardness: 7H

EXAMPLE 2

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, the content ofethylsilicate is increased for improving the film hardness; anddiacetonealcohol is added for improving the application characteristics.The constituents and the contents of the electroconductive organicpolymeric solution for forming the first coating layer 11 are asfollows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHYL SILICATE  1.00 wt. % ETHANOL57.69 wt. % ISOPROPANOL 10.00 wt. % PURE WATER 25.00 wt. % HYDROCHLORICACID (HCl, 35%)  0.01 wt. % N-METHYL-2-PYRROLIDONE  2.00 wt. % ETHYLCELLOSOLVE  2.00 wt. % DIACETONEALCOHOL  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1. Surface resistivity: 44*10⁴ ohms/sq.

2. Film hardness: 8H

EXAMPLE 3

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, the content of PEDT/PSS isincreased for improving the electroconductivity, and methylethylketone(MEK is added as a co-solvent for lowering the surface tension of thesolution and improving the application characteristics. The constituentsand the contents of the electroconductive organic polymeric solution forforming the first coating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.50 wt. % ETHYL SILICATE  0.50 wt. % ETHANOL57.99 wt. % ISOPROPANOL 10.00 wt. % PURE WATER 25.00 wt. % HYDROCHLORICACID (HCl, 35%)  0.01 wt. % ETHYL CELLOSOLVE  3.00 wt. % MEK(METHYLETHYLKETONE)  3.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 8*10³ ohms/sq.

2) Film hardness: 7H

EXAMPLE 4

The coating method is the same as that in EXAMPLE 1, but instead ofethyl silicate as a solvent in the electroconductive organic polymericsolution, butanol is used. The constituents and the contents of theelectroconductive organic polymeric solution for forming the firstcoating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHANOL 60.70 wt. % BUTANOL 10.00wt. % PURE WATER 25.00 wt. % PROPYLENE GLYCOL MONO METHYL ESTER  2.00wt. % ETHYL CELLOSOLVE  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 4*10³ ohms/sq.

2) Film hardness: 6H

EXAMPLE 5

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a solvent and a co-solventare changed for improving the electroconductivity. The constituents andthe contents of the electroconductive organic polymeric solution forforming the first coating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHYL SILICATE  0.50 wt. % ETHANOL58.19 wt. % METHANOL 10.00 wt. % PURE WATER 25.00 wt. % HYDROCHLORICACID (HCl, 35%)  0.01 wt. % N-METHYL-2-PYRROLIDONE  2.00 wt. % BUTYLCELLOSOLVE  2.00 wt. % ETHYL CELLOSOLVE  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 8*10³ ohms/sq.

2) Film hardness: 7H

EXAMPLE 6

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a content of pure water,and a solvent and a co-solvent are changed for improving the applicationcharacteristic. The constituents and the contents of theelectroconductive organic polymeric solution or forming the firstcoating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHYL SILICATE  0.50 wt. % ETHANOL58.19 wt. % METHANOL  3.00 wt. % ISOPROPYL ALCOHOL 17.00 wt. % PUREWATER 15.00 wt. % HYDROCHLORIC ACID (HCl, 35%)  0.01 wt. %N-METHYL-2-PYRROLIDONE  2.00 wt. % BUTYL CELLOSOLVE  2.00 wt. % ETHYLCELLOSOLVE  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 1*10⁴ ohms/sq.

2) Film hardness: 7H

EXAMPLE 7

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, contents of pure water andethylsilicate, and a solvent and a co-solvent are changed. Theconstituents and the contents of the electroconductive organic polymericsolution for forming the first coating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS  0.30 wt. % ETHYL SILICATE  0.40 wt. % ETHANOL58.29 wt. % METHANOL 10.00 wt. % ISOPROPYL ALCOHOL 10.00 wt. % PUREWATER 15.00 wt. % HYDROCHLORIC ACID (HCl, 35%)  0.01 wt. %N-METHYL-2-PYRROLIDONE  2.00 wt. % PROPYLENE GLYCOL MONO METHYL ESTER 2.00 wt. % ETHYL CELLOSOLVE  2.00 wt. %

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 6*10³ ohms/sq.

2) Film hardness: 7H

EXAMPLE 8

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a content of PEDT/PSS isdecreased. The constituents and the contents of the electroconductiveorganic polymeric solution for forming the first coating layer 11 are asfollows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS 0.10 ETHYL SILICATE 0.50 ETHANOL 70.39ISOPROPANOL 10.00 PURE WATER 15.00 HYDROCHLORIC ACID (HCl, 35%) 0.01N-METHYL-2-PYRROLIDONE 2.00 ETHYL CELLOSOLVE 2.00

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 1*10⁵ ohms/sq.

2) Film hardness: 8H

EXAMPLE 9

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a content of PEDT/PSS isremarkably decreased. The constituents and the contents of theelectroconductive organic polymeric solution for forming the firstcoating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS 0.005 ETHYL SILICATE 0.50 ETHANOL 80.485ISOPROPANOL 10.00 PURE WATER 5.00 HYDROCHLORIC ACID (HCl, 35%) 0.01N-METHYL-2-PYRROLIDONE 2.00 ETHYL CELLOSOLVE 2.00

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 3*10⁶ ohms/sq.

2) Film hardness: 8H

EXAMPLE 10

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a content of PEDT/PSS isextremely decreased. The constituents and the contents of theelectroconductive organic polymeric solution for forming the firstcoating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS 0.001 ETHYL SILICATE 0.50 ETHANOL 80.489ISOPROPANOL 10.00 PURE WATER 5.00 HYDROCHLORIC ACID (HCl, 35%) 0.01N-METHYL-2-PYRROLIDONE 2.00 ETHYL CELLOSOLVE 2.00

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 4*10³ ohms/sq.

2) Film hardness: 8H

EXAMPLE 11

The coating method is the same as that in EXAMPLE 1, but in theelectroconductive organic polymeric solution, a content of PEDT/PSS isremarkably increased. The constituents and the contents of theelectroconductive organic polymeric solution for forming the firstcoating layer 11 are as follows:

CONSTITUENTS OF THE ELECTRO- CONTENT CONDUCTIVE ORGANIC POLYMERICSOLUTION (wt. %) PEDT/PSS 0.65 ETHYL SILICATE 0.50 ETHANOL 31.84ISOPROPANOL 10.00 PURE WATER 53.00 HYDROCHLORIC ACID (HCl, 35%) 0.01N-METHYL-2-PYRROLIDONE 2.00 ETHYL CELLOSOLVE 2.00

In the result from the example above, the surface resistivity and thefilm hardness by means of a pencil test are as follows:

1) Surface resistivity: 6*10³ ohms/sq.

2) Film hardness: 5H

As found from the above-described Examples 1 to 11, within the scope ofthe appended claims according to the present invention, it is realizedto form, on the image display faceplate, the anti-static film 10comprising a first coating layer 11 of high-electroconductivitycontaining an electroconductive organic polymeric component. And, whenthe minimum of the ethyl silicate, i.e., only a binder is contained inthe electroconductive first coating layer 11, the electroconductivitycan be maximized.

That is, compared with the examples 1 to 7 and 11, the examples 8, 9 and10 shows the very high surface resistivity, thereby conspicuouslylowering the electroconductivity. Particularly, in less than 0.005 wt. %of PEDT/PSS as shown in the example 10, the electroconductivity becomesabruptly lowered, while, PEDT/PSS of above 0.005 wt. % is contained asshown in the example 11, the spin coating is difficult(the applicationcharacteristics become lowered and the film hardness becomes remarkablylowered due to the increase of the viscosity. Therefore, the content ofPEDT/PSS between 0.1 to 0.3 wt. % is found to be proper as anelectroconductive organic polymeric anti-static film for the imagedisplay faceplate.

Furthermore, the alkoxysilane solution is overcoating on the firstcoating layer 11 and permeated in the firs coating layer 11, therebymaking the silica film on the panel 2 and increasing the stickingstrength. Therefore, the first coating layer 11 becomes stronglyattached to the panel 2 and the film hardness increased.

Thus, the anti-static film 10 having an excellent shield effect′ againstelectromagnetic radiation and the superior anti-static characteristicscan be obtained. Further, compared with the conventional metallic oxidecoating, the manufacturing cost of the anti-static film 10 according tothe present invention becomes lowered and its method simpler. Also,deposition problem was not found, thereby making the coating on theexterior surface of the faceplate even without any spots. The reason isunderstood to be that the solution used in the present invention doesnot comprise any inorganic slurry.

FIG. 3 is an enlarged sectional view similar, in part, showing anelectroconductive organic polymeric anti-static film 20 formed on ageneral glass plate 2′ according to another embodiment of the presentinvention by means of the forementioned method.

In FIG. 3, the anti-static film 20 comprises a first coating layer 21formed containing an electroconductive organic polymeric component and asecond coating layer 22 of silica coating formed by being overcoatedonto the first coating layer 21, said anti-static film 20 having fineporosities 21′, as shown in FIG. 2. That is, the anti-static film 20comprises the first coating layer 21 having fine porosities 21′ with anexcellent electroconductivity, and the second coating layer 22penetrates through the porosities 21′ of the first coating layer 21 whenovercoated on the first coating layer 21, thereby being adhered to atleast the surface of the glass plate 2′. Therefore, the second coatinglayer 22 is very high in the film hardness and the adhesive strength.

In examples for the glass plate 2′, using an electroconductive organicpolymeric solution containing 0.005-0.5 wt. % ofpolyethylenedioxythiophene which polystyrenesulphonate is doped to asthe organic polymer of the first coating layer 21, and usingalkoxysilane Si(OR4(R is an alkyl group as a solution for making saidsecond coating layer 12, and similar to the above-described examples forthe panel 2, the coating structure of the electroconductive organicpolymeric film is formed as shown in FIG. 3, and each surfaceresistivity and each film hardness in the pencil test are similar tothose in each examples above for the panel 2.

Therefore, except for an image display faceplate, the anti-static film20 can be used for the general glass plate in which the anti-staticcharacteristic is required like a monitor protective cover and also, forthe shield effect against electromagnetic radiation or theanti-reflective effect.

Meanwhile, an anti-reflective layer 23 can be formed even in thisembodiment for a more effective anti-reflection as shown in phantom linein FIG. 3.

As understood from the above-described embodiments, the presentinvention enables an anti-static coating on a general glass plate havinghigh electroconductivity or superior anti-static characteristics, veryhigh sticking strength and film hardness, etc., and at the lowermanufacturing cost and in the simple manufacturing method. It should beclear to one skilled in the art that the present invention can bealtered and applied without any limitation to the aforementionedembodiments of the present invention and within the scope of the presentinvention's spirit.

What is claimed is:
 1. A solution for applying onto a surface of a glassplate 2′ in, order to form an anti-static film (10, 20), said solutioncontaining 0.005-0.5 wt. % of polyethylenedioxythiophene whichpolystyrenesulphonate is doped to, silicon alkoxide of below 10 wt. %,40-90 wt. % of at least one alcoholic solvent selected from a groupconsisting of a methanol, an ethanol, an isopropanol, a butanol, andcombinations thereof, 5-70 wt. % of pure water, and 1-20 wt. % of atleast one co-solvent selected from a group consisting of a compoundhaving a carbonyl group, an ether, and combinations thereof.
 2. Asolution according to claim 1, wherein said silicon alkoxide is of below2 wt. %.
 3. A method of making a solution for applying onto a surface ofa glass plate (2′) in order to form an anti-static film (10, 20), saidsolution being prepared by the steps of: dissolving in alcohol anaqueous solution of electroconductive organic polymers; first-addingsilicon alkoxide to the alcoholic solution for improving the cohesivestrength; and second-adding pure water and an inorganic acid catalystfor hydrolysis, and co-solvent for improving the application property.4. A method according to claim 3, wherein said alcoholic solvent is of40-90 wt. % and selected from a group consisting of a methanol, anethanol, an isopropanol, a butanol, and combinations thereof, whereinsaid electroconductive organic polymer is 0.005-0.5 wt. % ofpolyethylenedioxythiophene which polystyrenesulphonate is doped to,wherein silicon alkoxide is of below 10 wt. %, and wherein saidco-solvent is of 1-20 wt. % and is selected from a group consisting of acompound having a carbonyl group, an ether, and combinations thereof. 5.A glass plate on which an anti-static film (10, 20) is formed on theexterior surface, said film comprising: a first coating layer (11, 21),formed by coating an electroconductive organic polymeric solutioncontaining 0.005-0.5 wt. % of polyethylenedioxythiophene whichpolystyrenesulphonate is doped to, silicon alkoxide of below 10 wt. %;and a second coating layer (12, 22) of silica coating, formed by beingovercoated onto the first coating layer (11, 21).
 6. A glass plateaccording to claim 5, wherein said electroconductive organic polymericsolution contains 40-90 wt. % of at least one alcoholic solvent selectedfrom a group consisting of a methanol, an ethanol, an isopropanol, abutanol, and combinations thereof, 5-7 wt. % of pure water, and 1-20 wt.%. of at least one co-solvent selected from a group consisting of acompound having a carbonyl group, an ether, and combinations thereof. 7.A glass plate according to claim 5, wherein said second coating layer(12, 22) is formed by coating with alkoxysilane Si(OR)₄ (R is an alkylgroup).
 8. A glass plate according to claim 5, wherein said anti-staticfilm (10, 20) has an anti-glare characteristic itself, and otherwise atleast one anti-glare film (13, 23) formed thereon.
 9. A glass plateaccording to claim 5, wherein said glass plate includes an image displayfaceplate or a screen portion in a panel of a CRT (1).
 10. A glass plateon which an anti-static film (10, 20) is formed on the exterior surface,said film comprising: a first coating layer (11, 21) having fineporosities (11′, 21′) and an excellent electroconductive property formedby spin-coating an electroconductive organic polymeric solutioncontaining 0.005-0.05 wt % of polyethylenedioxythiophene whichpolystyrenesulphonate is doped to and silicon alkoxide of below 10 wt.%; and a second coating layer (12, 22) formed by being overcoated with amaterial of a strong adhesive strength onto the first coating layer (11,21) so as to adhere to at least the glass plate (2′) by penetratingthrough the porosities (11′, 21′) of the first coating layer (11, 21).11. A glass plate according to claim 10, wherein said second coatinglayer (12, 22) is formed by coating with alkoxysilane Si(OR)₄ (R is analkyl group).
 12. A glass plate according to claim 10, wherein saidglass plate includes an image display faceplate or a screen portion in apanel of CRT (1).
 13. A method of forming an anti-static film (10, 20)on a surface of a glass plate (2′), the method comprising the steps of:first-coating an electroconductive organic polymeric solution on thesurface of the glass plate 2′, said solution containing 0.005-0.5 wt. %of polyethylenedioxythiophene which polystyrenesulphonate is doped toand silicon alkoxide of below 10 wt. %; and second-coating alkoxysilaneSi(OR) ₄ after the first-coating step.
 14. A method according to claim13, wherein said electroconductive organic polymeric solution contains40-90 wt. % of at least one alcoholic solvent selected from a groupconsisting of a methanol, an ethanol, and isopropanol, a butanol, andcombinations thereof, 5-70 wt. % of pure water, and 1-20 wt. % of atleast one co-solvent selected from a group consisting of a compoundhaving a carbonyl group, an ether, and combinations thereof.
 15. Amethod according to claim 13, wherein the anti-static film (10, 20) isformed by-heat-treating the applied glass at a temperature of 180degrees centigrade after the second-coating step.
 16. A method accordingto claim 13, wherein the first-coating step and the second-coating stepare performed by one coating method selected from a spin-coating,spraying, dipping, and combinations thereof.